Bookinfo Spring Boot Reference Application

This application is modeled from the Istio Bookinfo application, but is 100% Spring Boot and has been built to model a production-grade application. Additionally, this application attempts to overcome some common hurdles and roadblocks that developers often run into.

This initial version doesn't have a dependency on Istio, but instead uses Hystrix for circuit breaker functionality. The goal is to move this application forward with Istio and remove the legacy Spring Cloud functionality.

Architecture

This application exhibits a stereotypical Spring Boot/Cloud microservice architecture for an application that is deployed to Kubernetes. It also has S2I and CI/CD capabilities baked in to leverage the OpenShift platform.

Microservices

bookinfo-details

This microservice take an ISBN number, and return book details by calling an external Google API.

(TODO) In the future, this service would benefit from caching of detail records.

(TODO) bookinfo-products

This microservice registers a product by using an ISBN and details from bookinfo-details. It will generate a consistent productId UUID based on the ISBN. This localized repository of books can be used to populate a catalog.

bookinfo-ratings

This microservice allows a reviewer to assign a rating (1-10) for a product. The ratings data is stored in a rating table in a ratings database.

bookinfo-reviews

This microservice allows a reviewer to write a free-form text review for a product. It also makes service calls to bookinfo-ratings to retrieve ratings information and also to add new ratings as they are submitted with reviews. The reviews data is stored in a review table in a reviews database. Additionally, the service calls to bookinfo-ratings go through a circuit breaker and have a retry mechanism .

Features

Basics

• pom.xml inherits from RHOAR BOM (Bill of Materials) and attempts to follow RHOAR booster conventions
• Includes Red Hat Maven repositories
• Multi-module with loose coupling between projects; each is independent except for common config
• Prevalent use of Lombok to minimize code for data objects
• Separate default and openshift Spring Boot profiles
• Separate default and openshift Maven profiles
• Use of Google Books API as an example 3rd party web service

Database

• Use of Spring Data and Hibernate as opposed to use JDBC APIs
• Separate Maven profiles for H2 and PostgreSQL, plus H2 for tests
• Strong preference to UUID database keys which work much better in a distributed system (i.e. microservices) as there will not be possible identifier collisions or synchronization issues.
• UUID values are stored in PostgreSQL in the native uuid type, which improves performance.
• PostgresH2UUIDType Custom Hibernate type to dynamically select UUID database type depending on if the PostgreSQL JDBC driver is available or not. If not available, UUIDs are stored as varchar in H2 which greatly improves SQL compatibility between PostreSQL and H2 when working with UUID data. The default UUID type for H2 is binary which creates compatibility issues with SQL.
• PostgreSQL compatibility mode enabled for H2 along with PostgreSQLDialect.
• Example of using data.sql to automatically insert values into an empty ephemeral database
• TODO: Disable data.sql for OpenShift profile
• TODO: Flyway database migrations
• TODO: Timestamps/auditing on database operations; will also assist in sorting to find the "latest" data by using a timestamp rather than a sequence number
• TODO: Connection pooling configuration for PostgreSQL

Spring Cloud

• Spring Cloud Config Kubernetes to gain access to secrets and configmaps through Kubernetes API
• Hystrix circuit breaker (with custom config)
• Hystrix Dashboard (for visualizing circuit breakers)
• Feign HTTP client with Hystrix integration and fallbacks
• FeignClient URL configurable through Spring Boot profiles
• FeignClient decoupled from target service code
• TODO: Replace Hystrix with Istio circuit breaker
• TODO: Feign Retries

APIs

• TODO: (In Progress, PoC Completed) API Gateway
• TODO: (In Progress, PoC Completed) Swagger with SpringFox

Frontend

• TODO: https://github.com/murphye/hybrid-react-angular-spring-boot-apps
• TODO: https://medium.com/@SumanthShankar/on-demand-login-with-keycloak-angular-4-5-ngrx-backend-api-bookmark-able-links-ecb065dc7993, https://github.com/mauriciovigolo/keycloak-angular, http://blog.keycloak.org/2018/02/keycloak-and-angular-cli.html
• TODO: https://github.com/patternfly/patternfly-ng

Security

• TODO: (In Progress, PoC Completed) Single Sign-On (Keycloak) Integration

OpenShift Template

• TODO: OpenShift

OpenShift S2I

• TODO: Custom builder for multi-module Maven project https://blog.openshift.com/maven-multi-module-projects-and-openshift

OpenShift + Jenkins CI/CD

• TODO: https://github.com/redhat-cop/container-pipelines/tree/master/multi-cluster-spring-boot
• TODO: https://github.com/redhat-cop/container-pipelines/tree/master/blue-green-spring
• TODO: https://github.com/redhat-cop/container-pipelines/tree/master/basic-spring-boot

Automated Testing

• TODO: JUnit 5 tests
• TODO: https://github.com/redhat-cop/container-pipelines/tree/master/cucumber-selenium-grid

Istio